This species is thought to be conspecific with T. equinum, although the latter represents the "+" mating strain of the same biological species Despite their biological conspecificity, clones of the two mating types appear to have undergone evolutionary divergence with isolates of the T. tonsurans-type consistently associated with Tinea capitis (particularly in children) whereas the T. equinum-type, as its name implies, is associated with horses as a regular host.

[4] A different simple method for identification at early stages is through the detection of chlamydospore-like structures (CLS), which are found on the reverse side of the culture under light microscopy.

[4] Trichophyton tonsurans causes tinea capitis infection globally, but it is especially endemic in Latin America (especially northern Brazil),[3] Mexico, and Africa.

[7] Transmission can occur through direct transfer, or through the use of shared resources and facilities such as pillows, couches, rugs, and pets, which should be thoroughly examined because they can be carriers of T.

[4] This species is a major cause of family and institutional outbreaks because of its persistent nature in indoor environments, and its ability to be transmitted through asymptomatic carriers.

During pathogenesis, the fungus undergoes protease elaboration to hydrolyze structural proteins (such as the keratin found in hair), and isolates show peak values between days 18–22 during the sporulation phase.

[10] In molecular studies of its virulence, common target genes include CarbM14, CER, and Sub2, which encode the proteases carboxypeptidase, ceraminidase, and subtilisin, respectively.

[3] This fungus has also been found to produce melanin, which may be phenotypically demonstrated through in vitro induction in caffeic acid media.

Melanin acts as an antioxidant molecule, providing protective properties to the fungus from damaging UV rays.

[1] The infection is often called "black dot ringworm" due to the small dark hair stubs that are found on the scalp.

[11] Although there are several treatments available, tinea capitis often has no subjective symptoms, so people at risk for infection should still receive fungal examinations regularly.